Existence of a 3.4 μm absorption band on asteroid (84) Klio

Ascertain whether asteroid (84) Klio exhibits a genuine 3.4 μm absorption band in its JWST/NIRSpec reflectance spectrum and, if present, determine the band center and depth to assess whether the feature is associated with complex organics and/or carbonates on its surface.

Background

The authors investigated potential absorptions near 3.4 μm—typically linked to complex organics and/or carbonates—by dividing Klio’s reflectance spectrum by a polynomial continuum and fitting a Gaussian. They found that the inferred band parameters vary substantially with the chosen continuum boundaries, reflecting the difficulty of defining a reliable continuum given the dominant 3 μm hydration feature.

Because the derived peak position and depth depend strongly on the continuum choice, the authors could not confirm the reality of a 3.4 μm absorption. Establishing whether this feature exists, and characterizing it if so, would directly inform the presence of carbon-bearing species on Klio.